Portable pneumatic drill.



A. P. STROM.

rbRTABLE PNEUMATIC DRILL.

APPLICATION FILED APR. 5. 1906.

Patented Dec. 15, 1908.

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A. P. STROM.

PORTABLE PNEUMATIG DRILL.

APPLICATION FILED APR. 5. 1906.

Patented Dec. 15, 1908.

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A. P. STROM.

PORTABLE PNEUMATIC DRILL. APPLICATION FILED Arms. 1906.

Patented Dec. 15, 1908. 4 SHEETS-SHEET 3.

A. P. STROM.

PORTABLE PNEUMATIC DRILL.

APPLIOATION FILED APR. 5. 1906. v

- Patented Dec. 15, 1908.

4 SHEETS-SHEET 4.

W 3 M. H 4 s 3% which the following is a UNITED STATES PATENT OFF CE.

ANDREW P. STROM, F CLEVELAND, OHIO, ASSIGNOR TO THE DAYTON PNEUMATIC TOOL COMPANY, OF DAYTON, OHIO, A CORPORATION OF OHIO.

ron'raiamr rimum'rrc Dam.

Specification of Letters Patent.

Patented Dec. 15,1908.

Application filed 5, 1906. Serial No. 809,982.

To all whom it may concern;

Be it known that I, Annanw P. STROM, a

citizen of the United States, .resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Portable Pneumatic Drills, of

specification, the

principle of the invention herein explained and the best mode in w ich I have contemplated applying that principle, so as to distinguish it from other inventions.

My invention relates to pneumatic tools and es ecially to certain improvements in portab e drills, and consists of means hereinafter fully described and specifically set forth in the claims.

.My improved neumatic portable drill comprises essentia y three important new features, as follows:

so that said valves ma .be actuated by only sides 0 one eccentric upon 't e crank-shaft, eac waive being connected tosaid eccentric by a suitable eccentric strap. I thus make the c linder heads serve also as a valve-chest, alt ough on account of expediency in manufacture I have made the chest a part'of the main cylinder castin in such a way that a strai ht line drawn mm the center of the cran to the center of the wrist-pin of the valve will be arallel with a line passing centrally througfi the cylinder from end to end and, consequently, parallel with the path of travel of the piston;

(2) A simple and efiective controlling valve-structure and arrangement combining in itself a reversing feature; and (3) The provision of only one bearing for the whole gear-end of the crank-shaft, including the ear or pinion on said shaft which engages wit the ear carried u on the tool socket, a suitab e opening eing made through the bearing and its socket to admit the teeth of'the latter gear, whereby I have really made two bearings in one, since this bearm acts upon the. crank-shaft on both f the pinion or gear, and thus the total number of bearings upon the whole crank is reduced to two, one at each end; whereas other similar. machines require three or more bearings whlch necessitate a great amount dle is inserted through them, and if they are left free to turn in their sockets until the shaft is in place.

I am aware that a disposition of controlling valves, embodying some of the features which I have described in (1) above, has

been heretofore made, but, in so far as I am in formed, it has always been confined to slide valves of the piston type, which, however,

have not been ositioned in the cylinder heads, nor have t ey been in the same verti cal plane as the cylinders with their axes at right angles to the latter; whereas I utilize the partially-rotatable Corliss valves ar- -of costly and unsatisfactory work in boring ran ed as hereinbefore mentioned and as will beere'inafter fully described. Whenever Corliss valves have heretofore been used in pneumatic drills, they have been positioned 111 such a way, relative to the crank and cylinders as to necessitate the use of two ormore eccentrics on the crank, one eccentric for each valve, or, if one eccentric was utilized for more than one valve, it was done through the medium of an eccentric strap or a lever composed of more than one part for each valve; whereas by my improvement one eccentric can be made to-serve for two'or more valves, each valve 0 erated by an eccentric stra comprising 0 y one piece.

T e annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting the preferred mechanical form in which the principle of the invention-ma be used,

In said annexecl drawin Figure 1 represents a vertical sectionaf elevation of the drill, taken upon the planes indicated by the lines 11, Fig. 2, the controlling valve embodying the means for reversing not being shown 111 this form of invention, the engine herein illustrated being designed to run in only one direction; Fig. 2 re resents a partial plan view and a partial horizontal section of the drill illustrated in Fig. 1 with the cover removed, showing the connections be tween the crank-shaft and the controlling valves; 3 represents anelevation of one of the controlling valves shown in 1, the

lower part thereof being partially shown in able construction; Fig. 5 represents a verti- .tive' connections being arr cal sectional view taken upon the planes indicated by the lines 55, Fig. 4, and looking in the direction indicated by the arrow,

showing the construction of the reversible controlling valves; Fig. 6 represents a layout or development of one of the reversible controlling valves; and Figs. 7 and 8 represent horizontal sections of said valve taken upon the'planes indicated bythe lines 7 7 and 8-8, respectively, Fig. 5.

My improved drill is of the piston type, with fixed cylinders having cylindrical controlling valves -fixed in what would otherwise be the-cylinder heads, as hereinbefore mentioned. '1 he pistons are connected to a crank-shaft which latter operates the drill spindle or the tool-socket by means of earing connecting the latter to said crank-s aft. The controlling valves are oscillated in their bushings from one eccentric upon' the crankshaft, connected by means of suitable rods to the respective valves, such rods or operaed substantially at right angles to each ot er. During the revolution ofthe crank-shaft, thevalves are oscillated by the eccentric to control the admission and exhaust of the fluid pressure to and from the working cylinders. These cylinders are preferably arranged in sets, usually a pair in each set, one above the other, there being two sets in the invention which I have illustrated, havin their central lo itudinal axes substantia ly at right 8132588 to one another. The valves are of the rotative plu ty e and each one is common to all-the cy in ers in any one set of cylinders. The fluid pressure is admitted .to the machine-body from any suitable source, preferably through a ho low handle,into a pressure chamber centrally-located between the outer ends of the cylinders, whence it passes through the valves into the working c linders, and thence is exhausted through t e valves. Said fluid pressure may pass from the pressure chamber through a central lon itudinal chamber in the valves into the wor in cylinders, and thence be exhausted throng said valves by means ofpassages in the outer surface of the latter, or it may enter such working cylinders throu h suc external passages in the valves an be exhausted through the central lon itudinal chambers in said valves, and it is t is latter form of construction that I prefer and have illustrated in the accompanying drawin although, obviously, the admission or 1scharge of the fluid pressure may be caused to occur either through the central passage or along the exterior assage of the valve, and such operations e ected alternately would themselves constitute a reversing feature.

In the form of construction illustrated in Figs. 4 and 5, the controlling valves are con nected by means of a yoke or any other suitable means to a reversing sleeve on the handle of the machine, or any other suitable manually-operated member, by means of which the valves are capable of being directly actuated to reverse the direction of the rotation of the crank-shalt, each of said controlling'valves of the reversible type having one exhaust passage which is common both to the normal and the reverse workings of theupper cylinders with which they are respectively associated; and a air of exhaust passages for the lower cylinders with which they are respectively associated, one of said pair acting as an exhaust passage for the normal working, and the other acting as an exhaust passage for the reverse working of said lower cylinders. The inlet of air to the cylinders from said reversible valves, however, is permitted from two passages, or rather from two edges of one generalexterior passage, so far as the upper cylinders with which said valves are associated are con-v cerned, one edge servi'n for the normal and the other edge serving or the reverse working of said cylinders; whereas, one inlet passage to said cylinders from said valves serves the lower cylinders.

A, A, and A A, respectively, cylinder A not bein 'shown in the drawings, any suitable flui pressure chamber A disposed between the respective pairs of cylinders and the controlling valves; and chambers A and A for said controlling valves. Suitably se-' cured to said outer casing A, and forming an end cap or cover therefor, is the member A.

Any suitable form of feed-screw head is illustrated at D, Fig. 1.

A and A are arranged in the cylinder heads the chamber A being arranged in the heads of the pair of cylinders A", A, and the chamber A being arranged in the heads of the pair of cylinders A and A". Said valve chambers have theircentral longitudinal axes arranged at right angles to the axes of the cylinders with which they are associated tween the planes being the same as the distance between the center of the valve and the axis of the wrist-pin to which the strap is fastened which connects the valve and the eccentric, Figs. 2 and I 4. The operative points of the valves, v i z., the points where the straps are fastened to them, are located at right angles to each other, and this is the for both the normal and reverse workings of- I have provided, in one casting, an ex-' terior casing A, two pairs of power-cylinders I It will benoted that the valve-chambers but not in the same plane, the distance berespectively, provided with suitable ports a and a communicating with the central pressure chamber A I Referring nowparticularly to the reversiblecontrolling valves shown in Figs. 4, 5, 6, 7, and 8, positioned within the bushings a and a are the controlling valves B and B, res ectively, provided with the exterior annu ar pressure chambers b and b communicating with the pressure chamber A and the respective pairs of cylinders, the latter communication being through the passages b Fig. 1 in the bushings a and a; said valves B and B are provided with exhaust ports b and b", respectively, in the upper parts of said valves, and if, b", 5 andb respectively, in the lower arts of said valves, said exhaust ports provi ing pressure communication by means of the passages b in the valve bushin s a and a, etween the respective sets of cy inders and the central axial passages and I), provided in said valves, respectively.

In the lower parts of the valves B and B are provided the passages 6 intermediate of the sets of exhaust passages b b and b b", respectively. Said passa es 1) form the sole ports for the entrance of live air from the pressure chambers b and b to the lower cyllnders A and A respectively, during both the normal and reverse workings of the machine. Live air is passed into the upper cylinders A and A during the forward working of the machine along the-edge e (Figs. 5 and 6) of the exterior passages b and b, and during the reverse working of the machine along the edge e thethrow of the valve during the reversing of the machine being substantially canal-to the distance between either of the e ges e and e and the edge of the exhaust passage 5 When the crankshaft is rotated in the normal direction the exhaust ports for the valve B are the ports 6 and b for the cylinders A and A respectively, and for the valve B the ports I) and b for the cylinders A and A,- res ectively. When the crank-shaft is rotate in the reverse direction, these func-.

tions are served by the ports I) and b 1; and b, res ectively.

In t e form of valve shown in Figs. 1, 2, and 3, the reversing element is omitted so that one of the-exhaust ports in the lower part of the valve is dispensed with, so that the upper and lower parts of the valve are similar. The controlling valves B B are so oscillated in their bushings by means of eccentric C that they control the inlet and exhaust of the fluid pressure to and from the working cylinders, the valves being provided farthest removed from said edge:

with disks 0 0 respectively, which are connected by means of eccentric rods 0 c and the wrist pins 0 c to the eccentric C. The disks to which the operative connections between said valve and the eccentric on the crank shaft are thus secured are fixed to the valve and may be made either integral therewith or as a separate piece. However, when the valve is designed to be reversed as shown in Figs. 5, 6, 7 and 8, an additional exhaust port must be provided, since the reversal of a valve throws one of the exhaust ports out of commission; this will be apparent from an inspection of the lay-out of the valve in Fig.

6. In the construction shown in Figs. 4 and I 5 in which the valves embody the reversing feature a triangular yoke C is fastened to stems c and 0 reduced diameters upon said stems bearing freely in the \ends of the cross-bar of said yoke, which is retained upon the stems by means of nuts 0? screwed upon threaded ends of said stemsc 'and c Said stems e and 0 are a part of the means which are provided as an element of the valve structure to reverse the valves, said stems having cut in them spiral grooves c which are engaged through a key or pin 0 to the disks 0 and c ,which disks can be rotated or oscillated only by the eccentric C-the ar rangement being such that when stems c and 0 are raised or lowered by the yoke C or by any other suitable means, said stems will artially rotate. The stems are engaged to the valve-structure proper by means of a feather-key 0 so that when the stems are raised or lowered by external means, the valves are rotated with the stems,

thus bringing the other set of ports into operative position relative to t e wrist-pins, eccentric and cylinders. The yoke C may be of any standard construction and may be actuated by any suitable means to raise and lower the controlling valves B and B. Located at the adjacent ends of the cylinders A, A", and A, A, is a crank chamber, in which is journaled in bearings c and c a crank-shaft C Fig. 1. I will call s ecial attention to the bearing 0, which is o a length sufficient to support the whole gear-end of the crank-shaft C, as will be noted from Fig. 1, said bearing having the-two end-portions 0" and e and the intermediate partial spherical portion 0 the whole hearing or s ell being incased in a socket C of the same inside conformat on and s1ze as the outside of the bearing 0. Carried upon sa d crankshaft and within said bearing 0 is a pinion C T which meshes with a gear C carried on the tool-socket so as to revolve the latter, said.

bearing c and the socket 0 being provided with suitable openings to receive the teeth of the gear 0 I The cylinders A A A and A, are provided with suitablepistons a, a, a, and a,

respectively, which are connected to cranks C and C, by means of the piston rods (1 a", a, and a respectively. lhe gear-end of the crank C and the gear are suitably atmosphere.

In operation, as will be evident from previous references to the specific action of the several elements constituting the device, fluid pressure, in the case in hand air, will be admitted to the machine body from any suitable source through the hollow handle into the pressure chamber A disposed between the respective pairs of valve chambers A,

A and corresponding cylinders. Having regard, then, to one valve only, the operation of the other being exactly the same, the fluid will be seen to'pass from such chamber A through the port 'a of the valve chamberbushing a into the exterior annular pressure chamber 1;. of the corresponding valve B. Thence thefluid is admitted to the power cylinders first one then the other by way of ports 6 Actuation of the piston in either of such cylinders and resulting oscillation of the valve will cut off this connection and substitute connection between the cylinder and exhaust ports b or b, as the case may be, by which the exhaust fluid is admitted into the hollow interior of the valve finally escaping from the valve through passage E into the open. Upon reversal the course of the fluid is substantially the same save that instead of orts b", b as previously explained, ports I) 5 serve as exhaust ports by reason of the changed angular relation of the valve to its operative connection, specifically eccentric rod 0. The above general description applies equally to the other valve B the arrangement of ports being exactly the same.

The improved construction, the simplicity, and other described advantages of m pneumatic drill all render it a mach ne whic produces power much superior in amount to that developed in any other drill or engine of the same size and type.

Having thus described In invention in detail, that which I par-ticu arly point out and distinctly claim is:-.

1. In a portable pneumatic drill, the combination of a casing; a pair of power-cylinders and a crank-chamber formed therein; controlling valves for said cylinders; a crankshaft located in said chamber; a pinion carried upon said crank-shaft; bearings for the latter, said pinion being wholly contained within one of said bearings; a gear carried upon the tool-socket of the machine and meshing with said pinion; pistons for said cylinders connected to said crank-shaft; and

operative connections between said valves and said crank-shaft.

2. In a portable pneumatic drill, the combination of a casing; a air of power-cylinders and a crank-cham er formed therein; controlling valves for said cylinders; a crankshaft located in said chamber; a sin le bearing for tlie -whole gear-end of sai crankshaft comprising a substantially cylindrical shell having lane ends and a sphericallysha ed centra ortion a pinion carried upon sai crank-shal within the spherical portion of said shell; a gear carried u on the toolsocket of the machine and meshing with said pinion; pistons for said cylinders connected to said crank-shaft; and operative connections between said valves and said crankshaft.

3. In mechanism of the class described, the combination of a power-cylinder; a piston working therein; a crank-shaft connected to said piston; a rotatable controlling valve for said cylinder; a stem longitudinally movable relatively to said valve but rotatably fixed thereto; a rod operatively connecting said valve with said crank-shaft, such connection with said valve being angularly adjustable by longitudinal movement of'said valve stem; and means for thus moving the latter.

4. In mechanism of the class described, the combination of a power-c linder; a piston working therein; a crank-s aft connected with said piston; a rotatable controlling valve for said cylinder; a rod operatively connecting said valve with said crank shaft; and a stem for thus connecting said rod with said valve, said stem being lon itudinally movable relatively to said rod an valve but being rotatably fixed with respect to the former and having helical engagement with respect to the latter. i

5. In mechanism of theiclass described, the combination of av plurality of power cylinders; pistons working therein; a crankshaft connected with said pistons; a rotatable controlling valve for each of said cylin- I ders; a stem longitudinally movable relatively to each of said valves but rotatably fixed thereto; a rod operatively connecting each of said valves with said crank-shaft, such connection with said valves being angularly adjustable by longitudinal movement of said valve stems; and means for simultaneously thus moving the latter.

6;- In a ortable neumatic drill, the combination oi a pair 0 power-cylinders pistons working therein; a crank-shaft connected to said pistons; controlling valves for said cylinders; operative connections between said valves and said crank-shaft; a yoke longitudinally secured to said valves, the latter being rotatable upon said yoke; means for raising and lowerin said yoke; and, means, in-

ture, adapted to reverse the latter upon the l actuation of the same by said yoke.

Z In a portable fpneumatic drill,.the combination of a pair 0 power-cylinders; pistons working therein; a crank-shaft connected to said pistons; oscillatory controlling valves for said cylinders; operative connections between'said valves and said crank-shaft; stems longitudinally movable relatively to said valves, rotatably fixed to the same, and having helical grooves; a *oke longitudinally secured to said stems, t e latter being rotatableupon said yoke; means for raising v and lowering said yoke; and means ada ted. to engage said grooves to reverse said va ves,

upon the actuation of said stems by said yoke. 8. In a portable pneumatic drill; the combination of a pair of power-cylinders; pistons working therein; a crank-shaft connected to said pistons; oscillatory controlling valves for said cylinders; disks connected to said connecting said valves; eccentric-straps crank-shaft and said disks stems secured to said valves'by means of feather-keys, intersect-ing said disks and having helical grooves;

keys fixed to said disks and adapted to engage with said grooves; a yoke longitudinally secured to said stems, the latter being 

